The Oakland City Council is expected to approve a new law today allowing police to arrest spectators at illegal sideshow car rallies and street races who "actively encourage" reckless driving.

The proposed ordinance, revised after the council last month rejected Mayor Jerry Brown's initial proposal on sideshows, is similar to laws against street racers in Fremont and Sacramento.

Oakland's move is the latest volley in the city's five-year campaign to end the illegal events, which police say increase crime and encourage motorists to recklessly show off before crowds.

"By stopping the crowds from egging these guys on, we can really get a handle on the sideshows," said Oakland Police Lt. Dave Kozicki, who heads the department's traffic unit. "We've made a lot of progress and this will make it even harder for these guys to take over intersections.

The new version of the law would make the penalties lighter for first- and second-time offenders. Police could arrest spectators for an infraction instead of a misdemeanor for the first and second offenses. First-time offenders could face a fine of $500, which would increase to $750 for the second offense. The third offense would be a misdemeanor, punishable by up to six months in jail and a fine of $1,000.

The new version also adds language clarifying that the penalties only apply to spectators who are "knowingly" within 100 feet of a sideshow and "who urge and assist participants through actions and/or words."

Sideshows have been going on in Oakland since the late 1980s, usually starting just before midnight on a Friday or Saturday and continuing into the wee hours of the morning.

Until the late 1990s, sideshows were often confined to the parking lots of shuttered businesses along Hegenberger Road or International Boulevard. But after the city passed an ordinance forcing businesses to chain off their lots after hours, the sideshows became huge moving caravans of as many as 200 cars.

Typically, some of the front cars will block the perimeter of an intersection while other cars spin doughnuts inside.

Councilwoman Jean Quan, who helped draft the compromise measure at the council Public Safety Committee, said at the time that she didn't want police to arrest people caught in traffic or watching innocently from their front porches.

"We wanted to be able to arrest people who show up for these sideshows and follow them around," Quan said. "We don't want them to have an audience."

Opponents said that by arresting spectators police are criminalizing young people -- usually African Americans and Latinos -- instead of offering safer forms of recreation. Councilwoman Desley Brooks wants the city to consider sanctioning car rallies or street racing in a parking lot, a move that would be similar to programs in San Diego and Los Angeles.

"The spectator ordinance would largely be enforced in East Oakland in communities of color," Brooks said Monday. "We want to have a safe and sanctioned event that is away from the neighborhoods; we don't want to use the term sideshow."

Kozicki said that people arrested at sideshows average 26 years old and that many of them have criminal records and are on parole or probation or have pending arrest warrants. He said that nearly half the motorists stopped by police are driving without valid licenses.

Even without the ordinance, police are making many arrests. Since May 7, police have arrested 179 people at sideshows, written 833 citations, recovered nine firearms and towed the cars of 333 unlicensed drivers.

Kozicki said that spectators are often robbed, beaten or sexually assaulted during sideshow events. Since November, there have been five homicides in which spectators were shot and killed during or near street races or sideshow events.

While the ordinance also targets spectators at street races, Kozicki said those have been less of a problem than sideshows.

Most street races in Oakland occur on a stretch of Middle Harbor Road near Seventh Street at the Port of Oakland that is virtually devoid of local traffic late at night, Kozicki said. Police and port officials may erect temporary barriers to prevent traffic unrelated to the port after 10 p.m., he said.

"Identifying spectators at street races is not such a big deal," Kozicki said. "There's really no other reason a person would stop in the middle of the night at the port."